Thirteen week rodent feeding study with grain from molecular stacked trait lepidopteran and coleopteran protected (DP-ØØ4114-3) maize

Subchronic feeding study of glyphosate-tolerant maize GG2 with the gr79-epsps and gat genes in Wistar Han RCC rats

The genetically modified (GM) maize GG2 contains gr79-epsps and gat genes, conferring glyphosate tolerance. The present study aimed to investigate potential effects of maize GG2 in a 90-day subchronic feeding study on Wistar Han RCC rats. Maize grains from GG2 or non-GM maize were incorporated into diets at concentrations of 25% and 50% and administered to Wistar Han RCC rats (n = 10/sex/group) for 90 days. The basal-diet group of rats (n = 10/sex/group) were fed with common commercialized rodent diet. Compared with rats fed with the corresponding non-GM maize and the basal-diet, no biologically relevant differences were observed in rats fed with the maize GG2, according to the results of body weight/gain, feed consumption/utilization, clinical signs, mortality, ophthalmology, clinical pathology (hematology, prothrombin time, urinalysis, serum chemistry), organ weights, and gross and microscopic pathology. Under the conditions of this study, these results indicated that maize GG2 is as safe as the non-GM maize in this 90-day feeding study.

A 90-day feeding study of genetically modified maize LP007-1 in wistar han RCC rats

LP007-1 is a variety of insect-resistant and herbicide-tolerant maize containing the modified cry1Ab, cry2Ab, vip3Aa and cp4-epsps genes. The food safety assessment of the maize LP007-1 was conducted in Wistar Han RCC rats by a 90-days feeding study. Maize grains from both LP007-1 or its corresponding non-genetically modified control maize AX808 were incorporated into rodent diets at 25% and 50% concentrations by mass and administered to rats (n = 10/sex/group) for 90 days. A commercialized rodent diet was fed to an additional group as the basal-diet group. The diets of all groups were nutritionally balanced. No biologically relevant differences were observed in rats fed with maize LP007-1 compared to rats fed with AX808 and the basal-diet with respect to body weight/gain, food consumption/utilization, clinical signs, mortality, ophthalmology, clinical pathology (hematology, prothrombin time, activation of partial thrombin time, serum chemistry, urinalysis), organ weights, and gross and microscopic pathology. Considering the circumstances of this study, the results provided evidence that LP007-1 maize did not exhibit toxicity in the 90-day feeding study.

A 90-day rodent feeding study with grain for genetically modified maize L4 conferring insect resistance and glyphosate tolerance

A 90-day rat feeding study was performed to conduct a safety assessment on L4, a multi-gene genetically modified maize, conferring "Bt" insect resistance and glyphosate tolerance. A total of 140 Wistar rats were assigned to seven groups, 10 animals/group/sex, which comprised three genetically modified groups fed diets containing different concentrations of L4, three corresponding non-genetically modified groups fed diets containing different concentrations of zheng58 (parent plants), and a basal diet group fed the standard basal diet for 13 weeks. The fed diets contained L4 and Zheng58 at w/w% percentages of 12.5%, 25.0%, and 50% of the total. Animals were evaluated on some research parameters, including general behaviour, body weight/gain, feed consumption/efficiency, ophthalmology, clinical pathology, organ weights, and histopathology. Throughout the feeding trial, all animals were in good condition. No mortality and no biologically relevant effects or toxicologically significant alterations were observed in the total research parameters of the rats in the genetically modified groups compared with those in the basal diet group or their corresponding non-genetically modified groups. No adverse effects were observed in any of the animals. The results indicated that L4 is as safe and wholesome as conventional, non-genetically modified control maize.

Subacute toxicity studies of meals prepared from genetically modified potato overexpressing the StDREB1 or the VvWRKY2 transcription factor in rats

BACKGROUND

Potato tubers from genetically modified plants overexpressing the StDREB1 or the VvWRKY2 transcription factors that exhibited improved tolerance to salt and resistance to Fusarium solani infection were characterized and evaluated for safety in a 30 day rat feeding study. Male Wistar rats were split into four groups and provided with a diet composed of 33% (w/w) of either one of the two genetically modified potatoes (GMPs), 33% of the commercial Spunta variety (Sp), or a control group fed with the basal rats' diet. The influence of the GMPs on rat behavior and overall health parameters was evaluated and compared with that of commercial potato (i.e. the Sp group) and control diet.

RESULTS

Small differences were noticed in the chemical composition of the different tubers, but all the diets were adjusted to an identical caloric level. Results showed no sign of toxic or detrimental effects on the rats' overall health as a result of these diets. The rats fed with the GMPs meal showed hematological and biochemical compositions of the plasma comparable to the control groups. No histopathological damage nor any structural disorganization, severe congestion, or acute inflammation were noticed in the rats' tissues.

CONCLUSION

Under these study conditions, the GMP diets did not induce any apparent or significant adverse effects on rats after 30 days of dietary administration in comparison with rats fed diets with the corresponding non-transgenic diet and the standard diet group. These two GMPs were therefore considered to be as safe as their commercial comparator. © 2022 Society of Chemical Industry.

DP-2Ø2216-6 maize does not adversely affect rats in a 90-day feeding study

Maize plants containing event DP-2Ø2216-6 (DP202216), which confers herbicide tolerance through expression of phosphinothricin acetyltransferase and enhanced grain yield potential via temporal modulation of the native ZMM28 protein, were developed for commercialization. To address current regulatory expectations, a mandatory 90-day rodent feeding study was conducted to support the safety assessment. Diets containing 50% by weight of ground maize grain from DP202216, non-transgenic control, and 3 non-transgenic reference varieties, were fully characterized, along with the grain, and diets were fed to Crl:CD®(SD) rats for at least 90 days. As anticipated, no biologically-relevant effects or toxicologically-significant differences were observed on survival, body weight/gain, food consumption/efficiency, clinical and neurobehavioral evaluations, ophthalmology, clinical pathology (hematology, coagulation, clinical chemistry, urinalysis), organ weights, or gross and microscopic pathology parameters in rats fed a diet containing up to 50% DP202216 maize grain when compared with rats fed diets containing control or reference maize grains. The results of this study support the conclusion that maize grain from plants containing event DP-2Ø2216-6 is as safe and nutritious as maize grain not containing the event and add to the significant existing database of rodent subchronic studies demonstrating the absence of hazards from consumption of edible fractions of genetically modified plants.

Safety evaluation of E12, W8, X17, and Y9 potatoes: Nutritional evaluation and 90-day subchronic feeding study in rats

The nutritional and health effects of four biotech potato events, E12, W8, X17, and Y9, were evaluated in a subchronic rodent feeding study. E12 contains pSIM1278 insert DNA derived from potato and designed to down regulate potato genes through RNAi. These changes result in reduced black spot and reduced acrylamide. W8, X17, and Y9 contain the DNA inserts from pSIM1278 and pSIM1678 to further reduce acrylamide and express a gene from wild potato that protects against late blight. Rats were fed diets containing 20% cooked, dried potatoes from these four events and three conventional potato varieties. Compositional analyses of the processed potatoes and the rodent diets demonstrated comparability between the four events and their respective conventional varieties. Rats consumed the diets for 90 days and were evaluated for body weight, dietary intake, clinical signs, ophthalmology, neurobehavioral parameters, clinical pathology, organ weights, gross pathology, and histopathology. No adverse effects were observed as a result of test diet consumption. These results support the conclusion that foods containing E12, W8, X17, or Y9 potatoes are as safe, wholesome and nutritious as foods from conventional potato varieties.

Rat feeding trials: A comprehensive assessment of contaminants in both genetically modified maize and resulting pellets

We analyzed a comprehensive set of contaminants in MON810 and NK603 genetically modified (GM) maize, and their non-GM counterparts, used in a rat feeding study (the GMO90 + project). Both the maize grains and the manufactured pellets were characterized. Only minor differences in contaminant levels between GM and corresponding non-GM harvests were evidenced. Fumonisin and deoxynivalenol mycotoxins were the pollutants present in the highest amounts, with concentrations that were however largely below acceptance reference values. Our data reporting slightly lower levels of fumonisin in MON810 compared to its non-GM counterpart corroborate the lower susceptibility of insect resistant Bt maize to fumonisin-producing fungi. Traces of glyphosate (0.016 mg/kg) were evidenced in grains from NK603 treated crops. Regarding the pellets, analysis of more than 650 potentially toxic substances revealed low amounts of various mycotoxins, pesticides and heavy metals. Concentrations of contaminants quantified in the pellets were however far below the maximum level of residues values set by regulatory agencies, and no substantial differences in contaminants between GM and non-GM pellets were observed. Moreover, when comparing the contamination status of grains and pellets, we demonstrate yet again that characterizing the grains is actually not sufficient to foresee the quality of the produced pellets.

On determining sample size in experiments involving laboratory animals

Scientists using laboratory animals are under increasing pressure to justify their sample sizes using a "power analysis". In this paper I review the three methods currently used to determine sample size: "tradition" or "common sense", the "resource equation" and the "power analysis". I explain how, using the "KISS" approach, scientists can make a provisional choice of sample size using any method, and then easily estimate the effect size likely to be detectable according to a power analysis. Should they want to be able to detect a smaller effect they can increase their provisional sample size and recalculate the effect size. This is simple, does not need any software and provides justification for the sample size in the terms used in a power analysis.

Safety Assessment of Food and Feed from GM Crops in Europe: Evaluating EFSA's Alternative Framework for the Rat 90-day Feeding Study

Regulatory-compliant rodent subchronic feeding studies are compulsory regardless of a hypothesis to test, according to recent EU legislation for the safety assessment of whole food/feed produced from genetically modified (GM) crops containing a single genetic transformation event (European Union Commission Implementing Regulation No. 503/2013). The Implementing Regulation refers to guidelines set forth by the European Food Safety Authority (EFSA) for the design, conduct, and analysis of rodent subchronic feeding studies. The set of EFSA recommendations was rigorously applied to a 90-day feeding study in Sprague-Dawley rats. After study completion, the appropriateness and applicability of these recommendations were assessed using a battery of statistical analysis approaches including both retrospective and prospective statistical power analyses as well as variance-covariance decomposition. In the interest of animal welfare considerations, alternative experimental designs were investigated and evaluated in the context of informing the health risk assessment of food/feed from GM crops.

Impact on environment, ecosystem, diversity and health from culturing and using GMOs as feed and food

Modern agriculture provides the potential for sustainable feeding of the world's increasing population. Up to the present moment, genetically modified (GM) products have enabled increased yields and reduced pesticide usage. Nevertheless, GM products are controversial amongst policy makers, scientists and the consumers, regarding their possible environmental, ecological, and health risks. Scientific-and-political debates can even influence legislation and prospective risk assessment procedure. Currently, the scientifically-assessed direct hazardous impacts of GM food and feed on fauna and flora are conflicting; indeed, a review of literature available data provides some evidence of GM environmental and health risks. Although the consequences of gene flow and risks to biodiversity are debatable. Risks to the environment and ecosystems can exist, such as the evolution of weed herbicide resistance during GM cultivation. A matter of high importance is to provide precise knowledge and adequate current information to regulatory agencies, governments, policy makers, researchers, and commercial GMO-releasing companies to enable them to thoroughly investigate the possible risks.

Safety assessment of GM plants: An updated review of the scientific literature

In a wide revision of the literature conducted in 2000, I noted that the information in scientific journals on the safety of genetically modified (GM) foods in general, and GM plants in particular, was scarce. Of course, it was not sufficient to guarantee that the consumption of these products should not mean risks for the health of the consumers. Because of the scientific interest in GM organisms (GMOs), as well as the great concern that the consumption of GM foods/plants has raised in a number of countries, I conducted two subsequent revisions (2007 and 2011) on the adverse/toxic effects of GM plants. In the present review, I have updated the information on the potential adverse health effects of GM plants consumed as food and/or feed. With only a few exceptions, the reported studies in the last six years show rather similar conclusions; that is to say, the assessed GM soybeans, rice, corn/maize and wheat would be as safe as the parental species of these plants. However, in spite of the notable increase in the available information, studies on the long-term health effects of GM plants, including tests of mutagenicity, teratogenicity and carcinogenicity seem to be still clearly necessary.

Safety assessment of foods from genetically modified crops in countries with developing economies

Population growth particularly in countries with developing economies will result in a need to increase food production by 70% by the year 2050. Biotechnology has been utilized to produce genetically modified (GM) crops for insect and weed control with benefits including increased crop yield and will also be used in emerging countries. A multicomponent safety assessment paradigm has been applied to individual GM crops to determine whether they as safe as foods from non-GM crops. This paper reviews methods to assess the safety of foods from GM crops for safe consumption from the first generation of GM crops. The methods can readily be applied to new products developed within country and this paper will emphasize the concept of data portability; that safety data produced in one geographic location is suitable for safety assessment regardless of where it is utilized.

Extending the Statistical Analysis and Graphical Presentation of Toxicity Test Results Using Standardized Effect Sizes

The results of repeat-dose toxicity tests are usually presented as tables of means and standard deviations ( SDs), with an indication of statistical significance for each biomarker. Interpretation is based mainly on the pattern of statistical significance rather than the magnitude of any response. Multiple statistical testing of many biomarkers leads to false-positive results and, with the exception of growth data, few graphical methods for showing the results are available. By converting means and SDs to standardized effect sizes, a range of graphical techniques including dot plots, line plots, box plots, and quantile–quantile plots become available to show the patterns of response. A bootstrap statistical test involving all biomarkers is proposed to compare the magnitudes of the response between treated groups. These methods are proposed as an extension rather than an alternative to current statistical analyses. They can be applied to published work retrospectively, as all that is required is tables of means and SDs. The methods are illustrated using published articles, where the results range from strong positive to completely negative responses to the test substances.

Spontaneous renal tumors in two rats from a thirteen week rodent feeding study with grain from molecular stacked trait lepidopteran and coleopteran resistant (DP-ØØ4114-3) maize

A thirteen week feeding study was conducted by feeding young adult male and female Sprague Dawley [Crl:CD®(SD)] rats diets containing grain from genetically modified (GM) DP-ØØ4114-3 maize that was either untreated (4114) or treated in the field with glufosinate ammonium (4114GLU). Control rats were fed diets containing the same concentration of near isogenic, non-GM maize grain (091) or one of three types of commercially available non-GM maize grain. At the end of the in-life phase, renal tubule tumors were reported in two male rats consuming diets containing 4114 maize grain. An expert panel of pathologists was convened as a Pathology Working Group (PWG) to review coded kidney histology sections from control (091) and treated (4114 and 4114GLU) male rats. The objectives were for the panel to characterize the histopathologic findings and to interpret their relationship to consumption of the indicated diet. The PWG concluded unanimously that the kidney tumors were characteristic of amphophilic-vacuolar (AV) tumors and AV atypical tubular hyperplasia which represent a distinctive phenotype that has been reported to occur sporadically in young Sprague Dawley Rats. The PWG determined that the neoplasms and atypical tubular hyperplasias were multicentric and bilateral which typifies tumors of familial origin. Degenerative/regenerative or cytotoxic changes consistent with nephrotoxicity leading to tumor induction were not observed in these rats and thus supports the conclusion that tumors were unrelated to consumption of the test diet. It was the unanimous opinion of the PWG that the proliferative renal tubule cell lesions were spontaneous and not related to consumption of diets containing 4114 maize grain.